Posted on by Nancy Atkinson

Voyager 1 Riding on a Magnetic Highway Out of the Solar System

Artist concept of NASA’s Voyager 1 spacecraft exploring a new region in our solar system called the “magnetic highway.” Credit: NASA/JPL-Caltech

The Voyager 1 spacecraft has not left the solar system, as was speculated earlier this year, but has now entered a new region at the edge of the solar system that scientists didn’t even know was there. It appears to be a “highway” of magnetic particles, shepherding Voyager 1 out into interstellar space.

“When you’ve gone where nothing has gone before, you expect to make new discoveries,” said Arik Posner, Voyager Program Scientist at a press briefing today.

“This is really another exciting step in the Voyager journey of exploration,” said Project Scientist Ed Stone. “Voyager’s discovered a new region of the heliosphere that we had not realized was there. It’s a magnetic highway where the magnetic field of the Sun is connected to the outside. So it’s like a highway, letting particles in and out.”

This artist’s concept shows plasma flows around NASA’s Voyager 1 spacecraft as it approaches interstellar space. Image credit: NASA/JPL-Caltech/JHUAPL

The heliosphere is a huge bubble of charged particles, and previously the Sun’s lower-energy charged particles have dominated. Now, Voyager 1 is in a region where it is surrounded almost entirely from cosmic rays from outside our solar system,as the lower-energy particles appear to be zooming out and higher-energy particles from outside are streaming in.

The first indication that something new was happening was on July 28 of this year when the level of lower-energy particles originating from inside our Solar System dropped by half. However, in three days, the levels had recovered to near their previous levels. But then the bottom dropped out at the end of August.

The two Voyager spacecraft have been heading outward since their launches 16 days apart in 1977. Voyager 1 is now near the edge of the solar system, and Voyager 2 is not far behind. Scientists feel this new region at the far reaches of our solar system is the final area the spacecraft has to cross before reaching interstellar space.

The Voyager team infers this region is still inside our solar bubble because the direction of the magnetic field lines has not changed. The direction of these magnetic field lines is predicted to change when Voyager breaks through to interstellar space.

“We believe this is the last leg of our journey to interstellar space,” Stone said. “Our best guess is it’s likely just a few months to a couple years away. The new region isn’t what we expected, but we’ve come to expect the unexpected from Voyager.”

Since December 2004, when Voyager 1 crossed a point in space called the termination shock, the spacecraft has been exploring the heliosphere’s outer layer, called the heliosheath. In this region, the stream of charged particles from the Sun, known as the solar wind, abruptly slowed down from supersonic speeds and became turbulent. Voyager 1’s environment was consistent for about five and a half years. The spacecraft then detected that the outward speed of the solar wind slowed to zero.

The intensity of the magnetic field also began to increase at that time.

“If we had only looked at the particle data alone, we would have said well, we’re out, goodbye solar system,” said Stamatios Krimigis, principal investigator for Voyager’s low-energy charged particle instrument. “We need to look at what all the instruments are telling us, because nature is very imaginative, and Lucy pulled out the football again.”

That’s because the magnetic field direction has not yet changed to the expected north-south orientation of interstellar space.

“We’re quite confident that there’s really no reason to believe we’re outside the heliosphere,” said Leonard Burlaga, with the Voyager magnetometer team. “There’s no evidence that we have entered the interstellar magnetic field. We are in a magnetic region unlike any we’ve been in before — about 10 times more intense than before the termination shock. The magnetic field data turned out to be the key to pinpointing when we crossed the termination shock. And we expect these data will tell us when we first reach interstellar space.”

As for the future of the spacecraft, which are powered by plutonium 238, they each lose about 4 watts of power a year and by 2020, the science team will have to start turning off instruments in order to conserve power. By 2025, there will probably not be enough power for any of the instruments to run, but there will be enough power to “ping” the spacecraft and have it answer. But by that time, they should be well out of the solar system. However, the spacecraft likely won’t encounter much, as it would take about 40,000 years for one of the Voyagers to reach another star system.

Voyager 1 is the most distant human-made object, about 18 billion kilometers (11 billion miles) away from the Sun. The signal from Voyager 1 takes approximately 17 hours to travel to Earth. Voyager 2, the longest continuously operated spacecraft, is about 15 billion kilometers (9 billion miles) away from our Sun. While Voyager 2 has seen changes similar to those seen by Voyager 1, the changes are much more gradual. Scientists do not think Voyager 2 has reached the magnetic highway.

Sources: Press briefing, JPL

Posted on by Nancy Atkinson

Curiosity Update: No Definitive Discovery of Organics…Yet

NASA’s Curiosity Mars rover documented itself in the context of its work site, an area called “Rocknest Wind Drift,” on the 84th Martian day, or sol, of its mission (Oct. 31, 2012). The rover worked at this location from Sol 56 (Oct. 2, 2012) to Sol 100 (Nov. 16, 2012). Image credit: NASA/JPL-Caltech/MSSS

The scientists from the Mars Science Laboratory mission had some good news and bad news at the much-anticipated briefing from the American Geophysical Union conference today. The good news is that all instruments are working well on the Curiosity rover, and they have found some potentially interesting compounds … organic compounds. The bad news is they are not sure if the organics are from Mars or not.

“SAM has no definitive detection to report of organic compounds,” said Paul Mahaffy, principal investigator for the Sample Analysis at Mars (SAM) instrument on the Curiosity rover.

This graph compares the elemental composition of typical soils at three landing regions on Mars: Gusev Crater, where NASA’s Mars Exploration Rover Spirit traveled; Meridiani Planum, where Mars Exploration Rover Opportunity still roams, and now Gale Crater, where the Curiosity rover is currently investigating. Credit: NASA/JPL-Caltech/University of Guelph

Interestingly – but not surprisingly – much of the data from the Curiosity rover is similar to previous Mars landers/rovers, such as Viking, the MER rovers and Phoenix. Curiosity’s instruments found chlorine, sulfur and water in Mars soil. Plus, remember the perchlorates that the Phoenix lander found on Mars four years ago? The Sample Analysis at Mars (SAM) instrument on Curiosity has “tentatively” identified perchlorate, which is an oxygen and chlorine compound, which is highly reactive. Reactions with other chemicals heated in SAM formed chlorinated methane compounds, which are one-carbon organics. The MSL scientists said that the chlorine is of Martian origin, but it is possible the carbon may be of Earth origin, carried along from Earth by Curiosity.

Something like this happened previously, where a detection of methane by the SAM suite of instruments turned out to be air that was brought along from Florida, as air leaked into the Tunable Laser Spectrometer (TLS) while the spacecraft was awaiting launch. The initial readings from the TLS, full of methane, were very exciting to the Curiosity scientists until they realized it was from Earth.

And so, with these latest data, the science team wants to make sure these organic compounds truly come from Mars, or if it is from contamination brought along to Mars onboard Curiosity. And one other fly in the ointment is that the organics could also be primordial material from the cosmos delivered to Mars from meteorites, and not be of Martian origin.

But the good news here is that MSL’s suite of instruments should be able to determine the origin of the organics, no matter when they come from.

“This is the first fully integrated measurement on the mission in which every instrument participated in analysis,” said Curiosity Project Scientist John Grotzinger. “And all the instruments working together can tell us if it isn’t originally from Mars… but there’s a complicated decision pathway, and we have to explore each one systematically.”

Grotzinger said they would have to decide whether or not those formation pathways are abiotic or biologic. But that will take a while, as this missions is “moving at the speed of science.”

“This mission is about integrated science,” he said. “No single measurement will produce a hallelujah moment… We are going to pull it all together and take our time and after that if we’ve found something significant we’ll be happy to report that.”

Grotzinger was asked about how his comments a few weeks ago to an NPR reporter were construed as suggesting that an “earth-shaking” discovery had been made by the team, setting off wild speculation of what the rover found.

“What I’ve learned from this is that you have to be careful about what you say,” he said during the briefing, “and even more careful about how you say it. We’re doing science at the speed of science. But we live in a world that’s sort of at the pace of Instagrams. The enthusiasm that we had, that I had, that our whole team has about what’s going on here, I think it was just misunderstood.”
“The great thing about this was, as the days went by, I thought it was terrific this mission has such wide appeal and public interest,” Grotzinger said.

The exciting part, Grotzinger said, is when you have multiple measurements by the instruments that provide similar results. “When we saw SAM replicating results, we knew team would have stuff to chew on for years to come. That’s why we were excited,” he said.

Mahaffy said before the mission, they knew terrestrial contamination could be an issue.

“We’ve gone to great care to address potential confusion that could be caused by terrestrial contamination,” he said. “We have an organic check material along, a silica glass. In the end, we will drill into organic check material that we brought along. If we see same stuff, then it may be terrestrial.”

The Mars Hand Lens Imager (MAHLI) on NASA’s Mars rover Curiosity acquired close-up views of sands in the “Rocknest” wind drift. Credit: NASA/JPL/MSSS

The Curiosity team purposely looked for an area to study that they thought would be rather benign. Curiosity took five scoops of soil from the Rock Nest site, basically a small sand dune. They found sand grains of various sizes, which Ken Edgett from the Hand Lens Imager team described as thick grains “like the salt grains on those big hot pretzels you can get” to much finer material with “grain sizes kind of like artificial sweeteners.”

This plot of data from NASA’s Mars rover Curiosity shows the variety of gases that were released from sand grains upon heating in the Sample Analysis at Mars instrument, or SAM. The gases detected were released from fine-grain material, and include water vapor, carbon dioxide, oxygen and sulfur dioxide. Credit: NASA/JPL-Caltech/GSFC

As we reported earlier, the first scoops were used to clean out the chemistry system. The real analysis of a sample came when it was heated to about 500°C and the gases that were released were studied. The most abundant gas was water from water, but the amount of water wouldn’t be enough to support any sort of life, the team said, even though it was higher than expected. And interestingly, the deuterium to hydrogen ratio on the surface of Mars is five times heavier than that in Earth’s oceans.

The scientists said this could be a result of Mars’ gradual loss of atmospheric material, in which lighter isotopes were preferentially lost.

The CheMin instrument found the Rock Nest samples were about half and half common volcanic minerals and non-crystalline minerals such as glass.

This map shows where the Curiosity has driven since landing at a site subsequently named “Bradbury Landing,” and traveling to an overlook position near beside “Point Lake,” in drives totaling 1,703 feet (519 meters). Credit: NASA/JPL-Caltech/Univ. of Arizona

Beyond that, the team focused on saying this is just the beginning of the mission with lots of time and potential science ahead.

“We’re working on a mission where it’s always going to be difficult to describe in a general way what we’re discovering,” said Grotzinger. “We do want to be very careful about each step along the way. MSL is a mission that is looking for habitable environments. And for that, we would need a source of water, a source of energy and a source of carbon, an essential building block for biological structures.”

Grotzinger said that what tends to happen is that a lot of attention is paid to the third component, and added that the news last week that organics were found on Mercury shows that organics are common in the solar system. And even though the Curiosity rover has already found a water source – the streambed in Gale Crater, along with the water in the soil — the issue is the relative non-abundance of the organics on Mars, so far.

“If we would have found something that was so abundant, that would have been a surprise for us,” he said.

See the JPL press release.

Posted on by Nancy Atkinson

Stunning Star Trails Mania

You like star trails? We’ve got star trails! One of our favorite timelapse gurus, Gavin Heffernan from Sunchaser Pictures shot this stunning footage, and as he says, no special effects of any kind are needed to create star trails: just leave your shutter open and the natural rotation of Earth takes care of the rest!

But wait… there’s more!

Have you ever compared how different star trails look in the northern hemisphere compared to the southern hemisphere?

César Cantú has:

From the northern hemisphere, stars appear to move counterclockwise around the north pole of the sky; but if you stand at any point in the earth’s southern hemisphere, the stars appear to move clockwise around the south pole of the sky. César, who mans the Chilidog Observtory, took star trail footage from Mexico and Africa and combined the two to create an incredible “Hemispheric Countersense” video. See more about it here.

Combining star trails from Mexico and Africa. Credit: César Cantú

Scene from Sunchaser Star Trails. Credit: Gavin Heffernan. Footage shot in Big Bear Lake, Joshua Tree, and also Canada. Used Canon 5D & 7D, with a 24mm/1.4 lens and a 28mm/1.8.

SUNCHASER STAR TRAILS from Sunchaser Pictures on Vimeo.

Posted on by Nancy Atkinson

Vision of the Future? SLS Model “Flies” in Wind Tunnel Test

NASA’s Space Launch System buffet model in NASA’s Langley Researcher Center’s Transonic Dynamics Tunnel. Image credit: NASA/LaRC

This week, researchers tested a ten-foot-long model of the new Space Launch System, NASA’s next big thing for launching humans beyond Earth orbit. The test was conducted at the Langley Research Center’s Transonic Dynamics Tunnel (TDT).

“This is a critical milestone for the design of the vehicle,” said Langley research engineer, Dave Piatak.

Data retrieved will help prepare SLS for its first mission in 2017, Exploration Mission-1 (EM-1), which will deliver an uncrewed Orion spacecraft to lunar orbit to check out the vehicle’s systems. But before SLS’s first flight, the safety vehicle must be demonstrated through analysis and testing. An important step in ensuring a safe flight to orbit is buffet wind-tunnel testing to help determine launch vehicle structural margins.

To do this, a wind-tunnel model is put through its paces at transonic and low supersonic speeds reaching up to Mach 1.2. Testing aerodynamics at these speeds is essential to understanding the structural interaction to the flow field around the vehicle and determining loads on the flight vehicle.

360 miniature sensors on the model’s surface are scanned by a data acquisition system scanning at thirteen thousand scans-per-second. Unlike the rigid SLS buffet wind-tunnel model, the real launch vehicle is quite flexible. The rocket will bend and shake in response to forces during flight, and engineers use tests like this to determine that the resulting bending loads and vibrations are within the launch vehicle’s safe limits.

NASA engineers are now analyzing the data, and will be used to help refine the design of the SLS vehicle before the full-size rocket is built for flight tests. After completing EM-1, SLS will perform its second mission in 2021, Exploration Mission-2, launching Orion with its first crew of astronauts to demonstrate orbit around the Moon.

Source: PhysOrg

Posted on by Nancy Atkinson

Familiar Sci-Fi Faces Pitch NASA Spinoffs

Spinoffs have never been the primary reason for space exploration, but as NASA has done things that have never been done before, space-derived products and technologies have been developed, producing some side benefits. Some of these little side benefits have ended up saving lives and changing life on Earth for the better.

NASA has recently released three new videos touting the benefits provided by various space ‘byproducts,” starring three well-known faces from sci-fi shows of the past: June “Lost in Space” Lockhart, William “Captain KirK” Shatner and Wil “Acting Ensign” Wheaton. The videos mention how science fiction has become science fact, resulting in new commercial products and services that are tangible returns on investments in space technology.

Continue reading “Familiar Sci-Fi Faces Pitch NASA Spinoffs”

Posted on by Nancy Atkinson

Brown Dwarfs Might Host Planets Too

This image shows the brown dwarf ISO-Oph 102, or Rho-Oph 102, in the Rho Ophiuchi star-forming region. Its position is marked by the crosshairs. This visible-light view was created from images forming part of the Digitized Sky Survey 2. Credit: ALMA (ESO/NAOJ/NRAO)/Digitized Sky Survey 2. Acknowledgement: Davide De Martin

Brown dwarfs inhabit a kind of fuzzy line between stars and planets: their mass is seemingly too small for them to be full-fledged stars and yet they are too large to be planets. These dim stars were only discovered in 1995 but current estimates say that brown dwarfs could be as numerous as normal stars in our galaxy. Now, astronomers have found a brown dwarf that has a dusty disc encircling it, just like the discs encircling regular, young stars. It contains millimeter-sized solid grains, and around other newborn stars, these discs of cosmic dust are where planets form. Astronomers say this surprising find challenges theories of how rocky, Earth-scale planets form, and suggests that rocky planets may be even more common in the Universe than expected.

Rocky planets are thought to form through the random collision and sticking together of what are initially microscopic particles in the disc of material around a star. These tiny grains are similar to very fine soot or sand. However, in the outer regions around a brown dwarf, astronomers expected that grains could not grow because the discs were too sparse, and particles would be moving too fast to stick together after colliding. Also, prevailing theories say that any grains that manage to form should move quickly towards the central brown dwarf, disappearing from the outer parts of the disc where they could be detected.

“We were completely surprised to find millimeter-sized grains in this thin little disc,” said Luca Ricci of the California Institute of Technology, USA, who led a team of astronomers based in the United States, Europe and Chile. “Solid grains of that size shouldn’t be able to form in the cold outer regions of a disc around a brown dwarf, but it appears that they do. We can’t be sure if a whole rocky planet could develop there, or already has, but we’re seeing the first steps, so we’re going to have to change our assumptions about conditions required for solids to grow,” he said.

Artist’s impression of the disc of dust and gas around a brown dwarf. Credit: ESO

Ricci and his team used the Atacama Large Millimeter/submillimeter Array (ALMA) for their observations. Even though the telescope is not completely finished yet, ALMA’s high resolution allowed the team to pinpoint carbon monoxide gas around the brown dwarf — the first time that cold molecular gas has been detected in such a disc. This discovery, along with the millimeter-size grains, suggest that the disc is much more similar to the ones around young stars than previously expected.

ALMA, located in the high-altitude Chilean desert is a collection of high precision, dish-shaped antennas that work together as one large telescope to observe the Universe in millimeter-wavelengths, enabling observations of extreme detail and sensitivity. Construction of ALMA is scheduled to finish in 2013, but astronomers began observing with a partial array of ALMA dishes in 2011.

The astronomers pointed ALMA at the young brown dwarf ISO-Oph 102, also known as Rho-Oph 102, in the Rho Ophiuchi star-forming region in the constellation of Ophiuchus. The brown dwarf has about 60 times the mass of Jupiter but only 0.06 times that of the Sun, and so has too little mass to ignite the thermonuclear reactions by which ordinary stars shine. However, it emits heat released by its slow gravitational contraction and shines dimly with a reddish color.

The astronomers were able to determine the grains in the disc are a millimeter or more in size.

“ALMA is a powerful new tool for solving mysteries of planetary system formation,” said Leonardo Testi from ESO, a member of the research team. “Trying this with previous generation telescopes would have needed almost a month of observing — impossibly long in practice. But, using just a quarter of ALMA’s final complement of antennas, we were able to do it in less than one hour!” he said.

When ALMA is completed, the team hopes to turn the telescope again towards Rho-Oph 102 and other similar objects.
“We will soon be able to not only detect the presence of small particles in discs,” said Ricci, “but to map how they are spread across the circumstellar disc and how they interact with the gas that we’ve also detected in the disc. This will help us better understand how planets come to be.”

Read the team’s paper (pdf)

Source: ESO

Posted on by Nancy Atkinson

Everybody Chill, NASA Says: No Martian Organics Found

Curiosity maneuvering her robotic arm and conducting a close-up examination of windblown ‘Rocknest’ sand dune. Credit: NASA/JPL-Caltech/Ken Kremer/Marco Di Lorenzo

Relax everyone. There are no little green men or even a hint of organics on Mars… not yet, anyway.

“Everybody, chill,” Tweeted the Curiosity rover today. “After careful analysis, there are no Martian organics in recent samples.”

Update: And also, the Curiosity rover did not find plastic Mardi Gras beads on Mars either. More about that below.

Rumor and speculation abounded (and yes, we admit being part of that) after an interview with Mars Science Laboratory scientist John Grotzinger indicated something “earth-shaking” could be announced soon. “This data is gonna be one for the history books. It’s looking really good,” Grotzinger was quoted by NPR.

Over a week later, NASA finally issued a statement that “speculation that there are major new findings from the mission at this early stage are incorrect,” and said that a news conference from the Fall Meeting of the American Geophysical Union (AGU) on Monday, December 3 will be an update about first use of the rover’s full array of analytical instruments to investigate a drift of sandy soil.

“One class of substances Curiosity is checking for is organic compounds — carbon-containing chemicals that can be ingredients for life. At this point in the mission, the instruments on the rover have not detected any definitive evidence of Martian organics,” the press release said.

The discussion on Twitter is that NASA perhaps didn’t do enough last week to quell the onslaught of conjecture and speculation. But most people in the US were scurrying off for the Thanksgiving holiday and perhaps didn’t notice a Tweet from the Curiosity Rover:

“What did I discover on Mars? That rumors spread fast online. My team considers this whole mission ‘one for the history books’.”

JPL’s press spokesperson Guy Webster told Universe Today’s Ken Kremer as much last week, saying “As for history books, the whole mission is for the history books. John was delighted about the quality and range of information coming in from SAM during the day a reporter happened to be sitting in John’s office last week. He has been similarly delighted by results at other points during the mission so far.”

So, while it won’t be “big” news, you may want to tune into the press conference anyway at 9 a.m. PST Monday, Dec. 3. Audio and visuals from the briefing also will be streamed online at: http://www.ustream.tv/nasajpl .

Bummed? NASA stressed today that Curiosity is less than four months into a two-year prime mission to investigate whether conditions in Mars’ Gale Crater may have been favorable for microbial life. While Curiosity is exceeding all expectations, and has already has found an ancient riverbed, there’s no earth-shaking news to report at this time.

But don’t be surprised if there are some remarkable discoveries still to come.

And about those plastic beads…

As a prank, someone put up a very convincing-looking JPL knock-off webpage saying the rover had found plastic beads on Mars, and a la The Onion, supposedly quoted real scientists. One look at the picture, however and it becomes obvious this is a fake, plus the writer puts Curiosity at Endeavour Crater, where the Opportunity rover is located. Phil Plait does his normal great job of explaining it all, so check out his post at his new home at Slate.

Fake beads on Mars. Image credit: Xevier Jenks

In the meantime, the Curiosity rover shared this cute video that also speculates a bit about what could be found on Mars:

Posted on by Nancy Atkinson

Water Ice and Organics Found at Mercury’s North Pole

A radar image of Mercury’s north polar region is shown superposed on a mosaic of MESSENGER images of the same area. All of the larger polar deposits are located on the floors or walls of impact craters. Deposits farther from the pole are seen to be concentrated on the north-facing sides of craters. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington/National Astronomy and Ionosphere Center, Arecibo Observatory

Over 20 years ago, radar-bright materials were seen in the north polar region on Mercury, and since then scientists have postulated that water ice could be hiding there in permanently shadowed regions. The latest data from the MESSENGER spacecraft – now orbiting the planet closest to the Sun – confirms that Mercury indeed does hold water ice as well as organic material within permanently shadowed craters at its north pole. Scientists today said that Mercury could hold between 100 billion to 1 trillion tons of water ice at both poles, and the ice could be up to 20 meters deep in places. Additionally, intriguing dark material which covers the ice could hold other volatiles such as organics.

The MESSENGER team published three papers this week in the journal Science, which present three new lines of evidence that water ice dominates the components inside the craters on Mercury’s north pole.

“Water ice passed three challenging tests and we know of no other compound that matches the characteristics we have measured with the MESSENGER spacecraft,” said MESSENGER Principal Investigator Sean Solomon at a briefing today. “These findings reveal a very important chapter of the story of how water ice has been delivered to the inner planets by comets and water rich asteroids over time.”

MESSENGER arrived at Mercury last year and data from the spacecraft’s neutron spectrometer and laser altimeter were used to make the observations at the planet’s north pole.

A layer of water ice several meters thick is illustrated in white. Abundant hydrogen atoms within the ice stop the neutrons from escaping into space. A signature of enhanced hydrogen concentrations (and, by inference, water ice) is a decrease in the rate of MESSENGER’s detection of neutrons from the planet. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Neutron spectroscopy measures average hydrogen concentrations within Mercury’s radar-bright regions, and scientists were able to derive the water ice concentrations from the hydrogen measurements.

“The neutron data indicate that Mercury’s radar-bright polar deposits contain, on average, a hydrogen-rich layer more than tens of centimeters thick beneath a surficial layer 10 to 20 centimeters thick that is less rich in hydrogen,” said David Lawrence, a MESSENGER Participating Scientist based at the Johns Hopkins University Applied Physics Laboratory and the lead author of one of the papers. “The buried layer has a hydrogen content consistent with nearly pure water ice.”

This image shows sunlight that reaches the Prokofiev crater floor and rim. The north-facing portions of the rim and interior remain in perpetual shadow, as do those of numerous other craters. Click on the image watch a movie which simulates approximately one half of a Mercury solar day (176 Earth days) and uses the digital terrain model derived from MLA measurements. Credit: NASA Goddard Space Flight Center/Massachusetts Institute of Technology/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.

Data from MESSENGER’s Mercury Laser Altimeter (MLA) — which has fired more than 10 million laser pulses at Mercury to make detailed maps of the planet’s topography — corroborate the radar results and Neutron Spectrometer measurements of Mercury’s polar region. Gregory Neumann of the NASA Goddard Flight Center, lead author of the second paper said the team used topographic data to develop illumination models for Mercury north polar craters, revealing irregular dark and bright deposits at near-infrared wavelength near Mercury’s north pole.

“The real surprise is that there were dark areas surrounding bright areas that were more pervasive than radar bright areas,” said Neumann at Thursday’s briefing. “They are a blanket that protects the bright volatiles that lie underneath.”

Neumann said that impacts of comets or volatile-rich asteroids could have provided both the dark and bright deposits, a finding corroborated in a third paper led by David Paige of the University of California, Los Angeles.

Paige and his colleagues provided the first detailed models of the surface and near-surface temperatures of Mercury’s north polar regions that utilize the actual topography of Mercury’s surface measured by MLA. The measurements “show that the spatial distribution of regions of high radar backscatter is well matched by the predicted distribution of thermally stable water ice,” he said.

A map of “permafrost” on Mercury showing the calculated depths below the surface at which water ice is predicted to be thermally stable. The grey areas are regions that are too warm at all depths for stable water ice. The colored regions are sufficiently cold for subsurface ice to be stable, and the white regions are sufficiently cold exposed surface ice to be stable. The thermal model results predict the presence of surface and subsurface water ice at the same locations where they are observed by Earth-based radar and MLA observations. Credit: NASA/UCLA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

According to Paige, the dark material is likely a mix of complex organic compounds delivered to Mercury by the impacts of comets and volatile-rich asteroids, the same objects that likely delivered water to the innermost planet. The organic material may have been darkened further by exposure to the harsh radiation at Mercury’s surface, even in permanently shadowed areas.

This dark insulating material is a new and intriguing piece of the story of Mercury that MESSENGER is seeking to unravel, said Solomon, and raises questions about what types of organics could be found there. Solomon added that Mercury may now become an object of interest for astrobiology, but said in no uncertain terms that none of the scientists think there is life on Mercury. This could, however, provide information about the rise of organics on Earth.

Additionally, the scientist said there is zero chance of liquid water on Mercury, even though temperatures in some regions would be conducive to liquid water. But with no atmosphere on Mercury, water wouldn’t stick around for long. “It would be ice or vapor really fast,” said Paige.

This schematic of MESSENGER’s orbit illustrates some of the challenges to acquiring observations of Mercury’s north polar region. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Solomon said that obtaining these measurements has not been easy and has not been quick. “Even at highest latitudes reached by MESSENGER, the spacecraft must look at an oblique angle to look at the north polar regions,” he said.

During its primary orbital mission, MESSENGER was in a 12-hour orbit and was at an altitude between 244 and 640 km at the northernmost point in its trajectory. Since April 2012, MESSENGER has been in an 8-hour orbit, shown above, and it has been at an altitude between 311 and 442 km at the northernmost point in its trajectory. Even from these high-latitude vantages, Mercury’s polar deposits fill only a small portion of the field of view of many of MESSENGER’s instruments.

But despite the challenges, Solomon said, the one and a half years of MESSENGER in orbit have now yielded clear results.

See more images and videos from the briefing here.

Sources: MESSENGER, NASA

Posted on by Nancy Atkinson

Full Moon and Friends, November 28, 2012

The full Moon rising with Jupiter and Aldebaran on November 28, 2012 in North Carolina, USA. Credit: Tavi Greiner.

The full Moon is a-rising tonight, and it is not alone. There are lots of other bright and beautiful stars and planets out there — some snuggling right up together — and already we’ve got astrophotographers out there capturing the views. Above, Tavi Greiner had a gorgeous view of the Moon, along with bright Jupiter and Aldebaran. November’s full Moon is known as the “Beaver Moon,” or “Frosty Moon,” and this year it is the smallest full Moon of 2012, since the Moon is at apogee, the farthest distance in its orbit around the Earth. There was also a penumbral lunar eclipse earlier today, depending on where you are…

See more below:

The Moon, along with Jupiter and its moons. Credit: Kevin Gassen

“This is a composite of two images of the Moon and Jupiter, taken in Central Texas, November 28th, with my Canon T2i,” writes Kevin Gassen. “The images were taken less than a minute apart, one each with the proper settings to capture the moon and Jupiter as seen. The images were combined in Photoshop Elements 6 with only minor contrast adjustments to the moon. Relative sizes were unchanged.”

Moon – Jupiter Conjunction, November 28, 2012. Credit: Gustavo Sanchez

Speaking of bright Jupiter, here’s a great view of the giant planet in all its glory near the Moon.

Corona around the Full Moon November 27, 2012. (The Pleiades are in amongst the clouds, too). Credit: Sculptor Lil

Visibility of penumbral lunar eclipse of November 28, 2012. Image Credit: Fred Espenak

The penumbral eclipse of the Moon occurred during the early dawn on Wednesday morning for western North America, and during the middle of the night for the longitudes of Australia and Japan, in late evening of the 28th local date for China and Southeast Asia, and early that evening for India. Eastern Canada and the USA couldn’t see it at all as it occurred after Moonset.

Saturn, Venus, & Mercury Conjunction on 11-28-2012. Credit: John Chumack

And early this morning John Chumack was out to capture a plethora of planets together. Saturn, Venus, and Mercury Conjunction – Planetary Alignment on 11-28-2012 06:39am E.S.T. Venus is the brightest between the house and tree , Saturn right above Venus, and Mercury is below in between the power lines.

We’ll add more images as they come in!

And if you want to know when the next full Moon is coming up, check out our Phases of the Moon app on either Google Play or the iTunes Store, and help support Universe Today.

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Posted on by Nancy Atkinson

International Space Station Making New Solar Observations

The International Space Station. Credit: NASA

This weekend the International Space Station will turn itself to face the Sun, enabling ESA’s SOLAR instrument to capture an entire rotation of the solar surface. This is the first time the Station has changed attitude for scientific reasons alone.

This instrument has been on the ISS since 2008, and for the first time will record a full rotation of the Sun. It began this effort on November 19, 2012, and on December 1, the Station will spend two hours turning about 7 degrees so that observations can continue. It will hold this angle for ten days before returning to its original attitude.

“We want to record a complete rotation of the Sun and that takes around 25 days,” said Nadia This, operations engineer at the Belgian User Support and Operations Centre that controls SOLAR.

SOLAR needs to be in direct view of the Sun to take measurements but the Space Station’s normal orbit obscures the view for two weeks every month.

All the international partners had to agree on changing the ISS’s orientation.

However, moving a 450-ton orbital outpost the size of a city block isn’t a simple undertaking. Aside from calculating the correct orbit to keep SOLAR in view of the Sun, other factors need to be taken into account such as ensuring the solar panels that power the Station also face the Sun. Additionally, communication antennas need to be reoriented to stay in contact with Earth and other scientific experiments must be adjusted.

The SOLAR instrument located on the exterior of the Columbus module on the ISS. Credit: ESA

The SOLAR instrument was originally designed to last about 18 months, but has been going strong for 5 years. It is installed on the outside of the ESA’s Columbus module.

The SOLAR payload consists of three instruments to the solar spectral irradiance throughout virtually the whole electromagnetic spectrum.

The three complementary solar science instruments are:

SOVIM (SOlar Variable and Irradiance Monitor), which covers near-UV, visible and thermal regions of the spectrum.
SOLSPEC (SOLar SPECctral Irradiance measurements) covers the 180 nm – 3 000 nm range.
SOL-ACES (SOLar Auto-Calibrating Extreme UV/UV Spectrophotometers) measures the EUV/UV spectral regime.

Scientists say SOLAR’s observations are improving our understanding of the Sun and allowing scientists to create accurate computer models and predict its behavior.

Source: ESA